<?php
// If there is some value => TRUE
if(5>2)     T
if(2>5)     F
if(true)    T
if(false)   F
if(-1234)   T
if(1234)    T
if(0)       F
if('Hello') T
if('0')     F
if(null)    F
if("")      F (quote without space)
if(" ")     T (quote with space)
